To Prevent Obesity, Just Be Sure to Floss

Sometimes critical thinking isn’t evident when the subject is obesity and its prevention. Publications linking dentists and dental floss floss to obesity risk serve to illustrate the phenomenon.

Without a hint of irony, people were publishing headlines recently that proclaimed “Dentists Help in the Fight Against Obesity.” All this mindless activity stemmed from an analysis that found lower obesity rates in counties with more dentists per capita. One might expect the same result for an analysis of attorneys per capita.

The folks who published this study bear some responsibility for encouraging the press to run wild. While they noted that “these data could not be used to assess causality,” they went on to say:

The correlation between the prevalence of dentists and obesity rates highlights the potential for dental professionals, as well as other primary care providers, to provide meaningful health education and support for improved nutritional behaviors.

That publication and the flurry of dumb headlines brings to mind a more responsible publication on the association between obesity and flossing. To make the point that this sort of analysis produces a lot of hogwash, the authors developed logistic regression models to examine the relationship. They found a robust association between flossing and severe obesity. They concluded by saying:

The strong associations between two causally unrelated oral and general lifestyle characteristics indicate that simplistic epidemiologic methodology is unlikely to provide insights into causal mechanisms of oral diseases or oral-systemic relationships.

We need more critical thinking about obesity, its causes, and strategies for prevention. Pet projects for preventing obesity must be examined for robust evidence of their effectiveness. Otherwise they are simply a disturbing waste — of resources and opportunity.

Click here for an example of the mindless stories of dentists preventing obesity. Click here for the study. Click here for the analysis of flossing and obesity.

Floss, photograph © Brett Jordan / flickr

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